A priest's collar adorns Greeley's neck, of course, and the title refers to the smoke issued from the Vatican when a new pope is chosen-but you don't have to be Catholic to enjoy the author's wise and witty latest (after Irish Gold). For all the ecclesiastical trappings, the real story here is ""the ancient and honorable art of politics, second only to poetry in Plato's view of things."" The source of that line is frequent Greeley narrator Auxiliary Bishop John Blackwood (Blackie) Ryan of Chicago, who spends almost as much time keeping his superior, Sean Cardinal Cronin, healthy as he does politicking during the election of the new pope. The just-deceased pope isn't named, but Greeley leaves little doubt that he's the present pontiff. As the cardinals assemble to elect a successor, the fictional, right-wing Corpus Christie Institute joins forces with the real-life Opus Dei and the Curia to block the candidacy of the leading liberal candidate. These conservative forces employ electronic eavesdropping, rumor-mongering and character assassination, but they aren't quite up to Ryan, who learned his politics in Chicago. Ryan, whose commentary alternates with other first- and third-person viewpoints, offers lively takes on the Church (""more often good theater these days than good religion""), the American hierarchy (""who didn't understand yet that a little bit authoritarian was like a little bit pregnant"") and the cardinals' mission: ""to elect a Pope who will not stand in the way of either the Holy Spirit or Jesus' message of love."" Included in the high-spirited storytelling are some rare snippets of Church history regarding married popes, early Christian women involved in Church rites and so on. Greeley knows his material and his opinions, and sets both into delicious spins here. Author tour. (June)